The worry for the Pittsburgh Steelers when Le'Veon Bell decided not to play this season was that first-year starting running back James Conner might suffer a significant injury. With Conner already declared out for Sunday's game in Oakland, the Steelers will go with a running back by committee approach against the Raiders and perhaps longer.

Rookie Jaylen Samuels and veteran Stevan Ridley will get the bulk of the carries in place of Conner. The Steelers also signed Trey Edmunds to the 53-man roster after he spent the first 13 weeks of the season on the practice squad.

"We have a great deal of confidence in Ridley and a great deal of confidence in Jaylen," Steelers head coach Mike Tomlin said. "Jaylen, of late, has been on the rise."

Conner will be difficult to replace. He is currently fifth in the NFL in rushing yards with 909 and has scored 12 touchdowns.

Samuels has 31 yards on 12 carries and Ridley has 56 yards on 18 carries. In recent weeks, Samuels has been the top backup and figures to get the first look against the Raiders. It was Samuels who entered the game against the Chargers when Conner was injured. He had two carries for 5 yards, but he caught three passes for 20 yards, including a 10-yard touchdown catch that tied the score late in the fourth quarter. It was his second touchdown of the season.

Ridley hasn't touched the ball in the past three games. In his last appearance against Carolina a month ago, he had 26 yards on eight carries, with most of them coming late in the game after Conner entered the concussion protocol.

Conner's injury comes at the most inopportune time. The Steelers are in the midst of a chase for the AFC North division title with the Ravens. The Steelers (7-4-1) hold a half-game lead over the Ravens (7-5) entering this weekend's games.

The Ravens have won their past two games while the Steelers have lost two in a row to be in this predicament.

The Steelers arrive in Oakland clinging to hopes of making the playoffs despite defection and injuries that leaving them digging deep for a starting running back. And the Raiders, who depart their birth home for Las Vegas by 2020, are lining up with players left over from a purge of top stars.

Truth be told, the Raiders and quarterback Derek Carr actually played fairly well the last few weeks and the Steelers have good reason to view this last visit to Oakland as a trap game. The Steelers' next game after Oakland is against the New England Patriots.

And after last week, the Raiders have served notice. Just ask the folks at the Raiders' future home. Vegas bookies dissed the Raiders last week as 15.5-point underdogs against the visiting Kansas City Chiefs, giving Oakland its biggest home negative point spread in 20 years.

The Raiders lost 40-33, but showed a very efficient offense that managed 442 yards, including 171 on the ground. The passing game showed efficient use of the run-pass option that relied on Carr's ability to (1) make the right pre-snap read and (2) influence the quick and athletic Chiefs' defense into doing what he wanted.

For a two-win team it was a thing of beauty that surely must bother a Pittsburgh defense that gave up 26 points in the second half last week in a fall-from-in-front, 33-30 loss to the Los Angeles Chargers.

The Steelers have some things they have to clean up if they want to beat the Raiders. They had a tough time defending Chargers quarterback Philip Rivers, who threw for 299 yards and two touchdowns. Rivers continually found receiver Keenan Allen matched up on linebackers as the Steelers tried to piece together a pass defense without safety Morgan Burnett and cornerback Cameron Sutton.

"As the game wore on, I think he really got comfortable with what he was looking at and was able to do some things and get them in some situations to move the chains in possession downs," Tomlin said. "As the game wore on, I think he got a sense of some of the things we were doing in some of our sub-packages. Playing without Morgan Burnett and Cameron Sutton really limited us in some of those things. I think as the game went on he pushed Keenan Allen inside and took advantage of some of those opportunities."

Carr is playing well and might be able to take advantage of the Steelers in the same way, Tomlin said. That's why it's important for the Steelers to get Burnett and/or Sutton back in the fold this week.

Tomlin had the opportunity to coach Carr in the Pro Bowl last winter and came away impressed with his makeup.

"I like his competitive spirit," Tomlin said. "He's a good communicator, a gym rat, an X's and O's type of a guy. He's going to challenge us in the ways that Philip Rivers challenged us, particularly as the game wore on. We better be thoughtful about mixing our looks up to keep him from catching up with us and attacking us in some of the schematic ways we were attacked last week."